When determining the sedimentation rate of blood corpuscles the blood is mixed with a citrate solution, after which the mixture is transferred to a pipette to a certain level, whereupon the pipette is placed in a stand. The transfer of the blood-citrate mixture can be made in different ways, e.g. by using the pipette as a suction pipe or by putting the pipette into a certain container, so designed that the pipette acts as a piston therein. In both these methods, the blood must be transferred from the blood sample syringe to a second vessel or container, from which the blood-citrate mixture is transferred to the pipette. Thus it is necessary to use several means and the risk of contamination during transfer is obvious. When transferring blood from such a container, where the pipette acts as a piston, it can occur that when the blood pillar has reached the determined level in the pipette, but the end of the pipette has not been pushed right down to the bottom of the container, that the blood pillar actually is so much longer than the blood quantity left in the container, whereby misleading readings are obtained. To an ever increasing extent blood samples are now taken according to the vacuum blood system, i.e. by using essentially evacuated containers provided with a sealing rubber stopper, which is punctured with a cannula with puncture tips at both ends, and where the vacuum in the container is utilized for sucking up a certain quantity of blood. The system offers a direct transfer of blood from the patients vein to a hermetically closed test tube, in which the citrate solution is contained. The risk of contamination of the blood and transmission of infection during the sampling and transport of the test tube to the laboratory is thereby avoided. Under strict security regulations, the rubber stopper of the test tube is removed in the laboratory and the transfer of blood to the pipette is done in conventional way, usually by using the pipette as a suction pipe, which is then dipped under the blood level in the test tube. The pipette with the blood pillar shall thereafter be moved to a stand with the risk of spillage and contamination. This system consequently solves the problem at the blood sampling only, but the above mentioned disadvantages of the transfer to the pipette for sedimentation reaction continue to exist.